Unblocking of the Gamow-Teller strength in stellar electron capture on neutron-rich germanium isotopes

Journal Article · Thu Mar 01 04:00:00 EST 2001 · Physical Review C

DOI:https://doi.org/10.1103/PhysRevC.63.032801· OSTI ID:40206153

Langanke, K; Kolbe, E; Dean, D J

We propose a new model to calculate stellar electron capture rates for neutron-rich nuclei. These nuclei are encountered in the core collapse of a massive star. Using the shell model Monte Carlo approach, we first calculate the finite temperature occupation numbers in the parent nucleus. We then use these occupation numbers as a starting point for calculations using the random phase approximation (RPA). Using the RPA approach, we calculate electron capture rates including both allowed and forbidden transitions. Such a hybrid model is particularly useful for nuclei with proton numbers Z<40 and neutron numbers N>40, where allowed Gamow-Teller transitions are only possible due to configuration mixing by the residual interaction and by thermal unblocking of pf-shell single-particle states. Using the even germanium isotopes {sup 68-76}Ge as examples, we demonstrate that the configuration mixing is strong enough to unblock the Gamow-Teller transitions at all temperatures relevant to core-collapse supernovae.

• Sponsoring Organization: (US)
• OSTI ID: 40206153
• Journal Information: Physical Review C, Journal Name: Physical Review C Journal Issue: 3 Vol. 63; ISSN 0556-2813
• Publisher: The American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CONFIGURATION MIXING
ELECTRON CAPTURE
FORBIDDEN TRANSITIONS
GERMANIUM ISOTOPES
NEUTRONS
NUCLEI
OCCUPATION NUMBER
PROTONS
RANDOM PHASE APPROXIMATION
RESIDUAL INTERACTIONS
SHELL MODELS
SUPERNOVAE